Some things should just be off-limits in a new relationship. No open door bathroom use. No 20-hour road trips. But perhaps the biggest budding romance killer may be a boyfriend who just can't let go of the past -- your past.

Case in point: some dudes just can't ignore the fact their girlfriend made sex tape with someone else. And if millions of people had actually seen said sex tape, well, there is no way he's gonna get over that. So I'm not surprised Kim Kardashian's film debut (with ex Ray J) is at the top of Kanye West's mind. Though mentioning that nasty piece of work in his new song "clique" is a big No-No, especially if he plans to make her his wifey someday. His insecurities about it will grow old fast and he risks annoying Kim as much as her ex Kris Humphries clearly does.

Here are four other old relationship mistakes your and your man should never bring up again:

What are other things you wish your man would just get over or forget?